Broadcast/multicast service is used to communicate the same information to a number of end devices. Traditionally broadcasting has been used to distribute radio and television channels to an audience. Broadcasting allows stations to transmit information to a large number of end devices efficiently. Wireless packet data networks used by mobile nodes, such as cell phones or personal digital assistants (PDA), typically send information directly addressed to a particular device (i.e., unicast). The typical wireless architecture requires processing to set up and maintain connections through to the end devices, which can be burdensome in terms of processing. Depending on the number of radio network controllers that are connected on the network, the data replication necessary for broadcast/multicast service can quickly become unsustainable depending on the network architecture.
As is generally know, “broadcast” tends to refer to point-to-multipoint communication where all people within a broadcast area receive the broadcast signals; “multipoint” generally refers to point-to-multipoint communication where specified users, such as subscribers, receive the multicasted signals. Unless the context indicates specifically otherwise, the term “multicast” will refer to multicast and broadcast, as broadcast is essentially a specific case of multicast.